title: Biodistribution and dosimetry of 195mPt-cisplatin in normal volunteers. Imaging agent for single photon emission computed tomography.
abstract: 195mPt-cisplatin is regarded as a promising imaging agent for optimizing dosage in patients receiving cisplatin chemotherapy.
  
  
  METHODS
  We investigated the whole-body distribution and radiation dosimetry of 195mPt-cisplatin in humans. Whole-body scans were obtained up to 144 h after intravenous injection of 112.4 MBq 195mPt-cisplatin in each of five subjects. Blood samples were taken at various times up to 144 h after injection. Urine was collected up to 114 h after injection for calculation of renal clearance and whole-body clearance. Time/activity curves were generated by fitting the organ-specific geometric mean counts, obtained from regions of interest, on the respective images as a function of the time after injection. OLINDA software package was applied to calculate the absorbed radiation dose for various organs.
  
  
  RESULTS
  Most of the activity (32 ± 4%) was excreted in the urine during the first 5 h. The effective clearance half-life derived from extrapolation of the whole-body curve was 40 hours (1.7 days). On average, the highest dose was received by the kidneys (mean dose received 2.68 ± 1.5 mGy/MBq), followed by the spleen (mean dose received 1.6 ± 0.8 mGy/MBq) followed by the liver (mean dose received 1.45 ± 0.38 mGy/MBq). The estimated mean effective dose for the adult subject was 0.185 ± 0.034 mSv/MBq.
  
  
  CONCLUSIONS
  195mPt-cisplatin proved a safe radiopharmaceutical with a favourable biodistribution for early and delayed imaging of pathology above the diaphragm. The ED obtained was 0.185 ± 0.034 mSv/MBq. The highest organ dose was received by the kidneys (2.68 ± 1.5 mGy/MBq).
authors.affiliation: Prof. Dr. Mike Sathekge, University of Pretoria, Steve Biko Academic Hospital Private Bag X169, Pretoria 0001, South-Africa, Tel. 01 23 54 17 94, Fax 01 23 54 12 19, E-mail: mike.sathekge@up.ac.za.
authors.forename: M
authors.initials: M
authors.lastname: Sathekge
authors.forename: J
authors.initials: J
authors.lastname: Wagener
authors.forename: S V
authors.initials: SV
authors.lastname: Smith
authors.forename: N
authors.initials: N
authors.lastname: Soni
authors.forename: B
authors.initials: B
authors.lastname: Marjanovic-Painter
authors.forename: C
authors.initials: C
authors.lastname: Zinn
authors.forename: C
authors.initials: C
authors.lastname: Van de Wiele
authors.forename: Y
authors.initials: Y
authors.lastname: D'Asseler
authors.forename: G
authors.initials: G
authors.lastname: Perkins
authors.forename: J R
authors.initials: JR
authors.lastname: Zeevaart
mesh_terms: D000328:Adult; D002945:Cisplatin / Q000008:administration & dosage / Q000493:pharmacokinetics*; D064368:Healthy Volunteers; D006801:Humans; D007275:Injections, Intravenous; D008657:Metabolic Clearance Rate; D009928:Organ Specificity; D010984:Platinum / Q000008:administration & dosage / Q000493:pharmacokinetics*; D011829:Radiation Dosage; D011868:Radioisotopes / Q000008:administration & dosage / Q000493:pharmacokinetics*; D012016:Reference Values; D014018:Tissue Distribution; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D051598:Whole Body Imaging / Q000379:methods*; D014915:Whole-Body Counting
chemical_list: D011868:Radioisotopes; D010984:Platinum; D002945:Cisplatin
keywords: 195mPt-cisplatin; biodistribution; normal volunteers